Search results for "Microfluidic"

Macromolecules in Microfluidics: A Synergy for Systems Engineering

2017

Development of micro chemical, biological and thermal systems in China: A review

2010

The interest in micro technologies for application in chemical, biological and thermal systems has increased considerably in China because microreactors or microfluidics in general demonstrate some remarkably advantages such as inherent miniaturization and portability, intensification of heat and mass transfer, quick analysis results, high-throughput and low consumption of reagents. This review focuses on the recent advances in the micro technologies in China including microreactor-based systems for chemical processing and analysis, biological microfluidics for DNA analysis, cell handling and analysis, separation based detection, protein based applications and immunoassays, micro heat trans…

Microflow Technology in Polymer Synthesis

2012

Microflow technology, i.e., the use of microfluidic devices for continuous flow synthesis, represents a highly useful and increasingly popular method in organic chemistry. Recently, also an increasing number of polymer synthesis protocols attain benefit from this technique. In particular, the control of highly exothermic, fast polymerization reactions can be improved due to the excellent heat and mass transfer within the small dimensions of the microreactors. Continuous flow setups with different micromixer geometries and flow patterns are currently used for the preparation of a variety of macromolecular architectures by ionic and (controlled) radical polymerization techniques. This Perspec…

Configurable low-cost plotter device for fabrication of multi-color sub-cellular scale microarrays.

2014

We report on the construction and operation of a low-cost plotter for fabrication of microarrays for multiplexed single-cell analyses. The printing head consists of polymeric pyramidal pens mounted on a rotation stage installed on an aluminium frame. This construction enables printing of microarrays onto glass substrates mounted on a tilt stage, controlled by a Lab-View operated user interface. The plotter can be assembled by typical academic workshops from components of less than 15 000 Euro. The functionality of the instrument is demonstrated by printing DNA microarrays on the area of 0.5 squared centimeters using up to three different oligonucleotides. Typical feature sizes are 5 μm diam…

Design and fabrication of an acoustic micromixer for biological media activation

2014

International audience; The bioassay of infinitesimal quantities of protein markers in biological samples is the way to early cancer detection. However, this detection can be limited by the diffusion of these macromolecules (analytes) from the bulk to the sensor chip (surface of ligands). Here, we propose a new method to overcome this drawback by the activation of the biological media during the detection step. The principle consists in using ultrasonic vibrations in order to disrupt the equilibrium states of such biomolecular reactions and performing simultaneous detection inside an acoustic micromixer. Technological realization and initial characterizations of the device have been perform…

Axial dispersion of Brownian colloids in microfluidic channels

2016

Optofluidic microconvection with magnetic nanoparticles: Novel interaction of thermal diffusion and magnetic field

2021

Abstract Light-matter interactions are exploited in many applications, whereas superparamagnetic nanoparticles allow to introduce magnetic field control in diverse fluid environments. We study the structure of laser-induced thermal lens in thin layers of ferromagnetic colloid and predict significant magnetoconvective motion around the beam spot. It was found that localized heating depletes/accumulates magnetic nanoparticles in the beam-spot by thermal diffusion and collective magnetic interactions of nanoparticles produce strong microconvective currents. This mode of mass transport can be controlled by magnetic field. We expect the novel magnetosolutal microconvective coupling, which we des…

Active mixing inside double emulsion segments in continuous flow

2015

Fast mixing is essential for many microfluidic applications, especially for flow at low Reynolds numbers. A capillary tube-in-tube coaxial flow setup in combination with a glass microreactor was used to produce immiscible multiphase segments. These double emulsion segments are composed of an organic solvent as the shell (outer) phase and a completely fluorinated liquid (Fluorinert® FC-40) as the core (inner) phase. Due to the higher density of the core droplets, they are responsive to changing their position to the force of gravity (g-force). By gently shaking or jiggling the reactor, the core drop flows very fast in the direction of the g-field without leaving the shell organic phase segme…

Time-resolved velocity measurements in a magnetic micromixer

2015

Abstract Mixing efficiency is lower in passive micromixers due to viscous forces and substantial research effort is focused on designing high performance micromixers. Active micromixers make use of external forces to enhance mixing efficiency. Among these, magnetic forces are popular because they are non-contact and therefore the micromixer design can be kept simple. Laser-based diagnostic tools have great potential in providing multi-parameter information in microfluidics research on mixing. MicroPIV experiments are performed to investigate the transient flow field in a magnetic micromixer undergoing labyrinthine instability. Velocity and interface front information is extracted from a seq…

Distributed and Lumped Parameter Models for the Characterization of High Throughput Bioreactors

2016

Next generation bioreactors are being developed to generate multiple human cell-based tissue analogs within the same fluidic system, to better recapitulate the complexity and interconnection of human physiology. The effective development of these devices requires a solid understanding of their interconnected fluidics, to predict the transport of nutrients and waste through the constructs and improve the design accordingly. In this work, we focus on a specific model of bioreactor, with multiple input/outputs, aimed at gen- erating osteochondral constructs, i.e., a biphasic construct in which one side is cartilagi- nous in nature, while the other is osseous. We next develop a general computat…